The present disclosure relates generally to bearing assemblies and, more specifically, to sealed bearing assemblies.
Gas turbine engines typically include a compressor, a combustor, and at least one turbine. The compressor may compress air, which may be mixed with fuel and channeled to the combustor. The mixture may then be ignited for generating hot combustion gases, and the combustion gases may be channeled to the turbine. The turbine may extract energy from the combustion gases for powering the compressor, as well as producing useful work to propel a craft (e.g., aircraft), such as by driving a fan or propeller, or to power a load, such as an electrical generator.
Rotating turbomachinery, such as that found in gas turbine engines, frequently contains one or more bearing assemblies to support rotating components within stationary housings or between or within other rotating apparatus. At least some known bearing assemblies are positioned within structural compartments known as “sumps,” in which the bearing assembly is open to the entire sump cavity. The bearing is lubricated by spraying oil directly onto the bearing or onto an adjacent component that routes the oil into the bearing. The oil may drain away from the bearings into the sump cavity, which is sealed by a plurality of seals. These seals rely on a flow of air entering the sump to prevent oil from leaking out of the sump cavity. Due to the size and shape of the sumps, and speed of the bearings, the sump contains a frothy mixture of oil and air. These known bearing assemblies can be bulky and relatively heavy, and use large quantities of oil that must be stored, pumped, filtered, and cooled. Moreover, these bearing assemblies consume power through heat rejection into the oil and through air flow into the sump cavity.